Biofilm formation and Antibiotic susceptibility pattern among Staphylococcus aureus in a tertiary care hospital in Kanchipuram: An Evaluation of screening methods for biofilm formation (original) (raw)

Biofilm formation by clinically isolated Staphylococcus Aureus from India

The Journal of Infection in Developing Countries

Introduction: Staphylococcal biofilms are prominent cause for acute and chronic infection both in hospital and community settings across the world. Current study explores biofilm formation by Staphylococcus aureus isolates from clinical samples by different methods. Methodology: Standard techniques used for the characterization of S.aureus. Qualitative and quantitative biofilm formation was assessed by Congo red Agar, Tube and Microtiter plate methods. Results: A total of 188 clinical isolates of S.aureus were screened for biofilm formation and 72 (38.29%) of them were found to be biofilm producers, 34 (18.08%) strong, 38 (20.21%) moderate. The remaining 116 (61.7%) were weak/ non biofilm producers. Maximum biofilm formers were recorded in pus samples (39.06%), followed by isolates from blood (38.23%) and urine (34.61%). Statistical analysis for the formation of biofilm indicated that Microtiter plate method is the most sensitive and specific method for screening biofilm production....

Antibiotic resistance and biofilm production among the strains of Staphylococcus aureus isolated from pus/wound swab samples in a tertiary care hospital in Nepal

Annals of Clinical Microbiology and Antimicrobials

Background: The increasing drug resistance along with inducible clindamycin resistance, methicillin resistance and biofilm production among the strains of Staphylococcus aureus are present as the serious problems to the successful treatment of the infections caused by S. aureus. So, the main objectives of this study were to determine the antimicrobial susceptibility patterns along with the rates of inducible clindamycin resistance, methicillin resistance and biofilm production among the strains of S. aureus isolated from pus/wound swab samples. Methods: A total of 830 non-repeated pus/wound swab samples were processed using standard microbiological techniques. The colonies grown were identified on the basis of colony morphology, Gram's stain and biochemical tests. Antimicrobial susceptibility testing was performed by Kirby-Bauer disc diffusion technique. Detection of inducible clindamycin resistance was performed by D test, while detection of methicillin resistant S. aureus (MRSA) was performed by determination of minimum inhibitory concentration of oxacillin by agar dilution method. Similarly, detection of biofilm formation was performed by microtiter plate method. Strains showing resistance to three or more than three different classes of antibiotics were considered multidrug resistant. Results: Total 76 samples showed the growth of S. aureus, among which 36 (47.4%) contained MRSA and 17 (22.4%) samples were found to have S. aureus showing inducible clindamycin resistance. Among the S. aureus isolated from outpatients, 41.9% were MRSA. Highest rates of susceptibility of S. aureus were seen toward linezolid (100%) and vancomycin (100%). Similarly, S. aureus isolated from 35 (46.1%) samples were found to be biofilm producers. Higher rate of inducible clindamycin resistance was seen among MRSA in comparison to methicillin susceptible S. aureus (MSSA). Similarly, higher rates of multidrug resistance and methicillin resistance were found among biofilm producing strains in comparison to biofilm non producing strains. Conclusions: The rate of isolation of MRSA from community acquired infections was found to be high in Nepal. Increased rate of inducible clindamycin resistance as compared to previous studies in Nepal was noted. So for the proper management of the infections caused by S. aureus, D test for the detection of inducible clindamycin resistance should be included in the routine laboratory diagnosis. Further, detection of biofilm production should also be included in the routine tests. Linezolid and vancomycin can be used for the preliminary treatment of the serious infections caused by S. aureus.

Study on biofilm-forming properties of clinical isolates of Staphylococcus aureus

The Journal of Infection in Developing Countries, 2012

Introduction: The purpose of this study was to observe the formation of biofilm, an important virulence factor, by isolates of Staphylococcus aureus (S. aureus) in Pakistan by different conventional methods and through electron microscopy. Methodology: We screened 115 strains of S. aureus isolated from different clinical specimens by tube method (TM), air-liquid interface coverslip assay method, Congo red agar (CRA) method, and scanning electron microscopy (SEM). Results: Out of 115 S. aureus isolates, 63 (54.78%) showed biofilm formation by tube method. Biofilm forming bacteria were further categorized as high producers (n = 23, 20%) and moderate producers (n = 40, 34.78%). TM coordinated well with the coverslip assay for strong biofilm-producing strains in 19 (16.5%) isolates. By coverslip method, weak producers were difficult to differentiate from biofilm negative isolates. Screening on CRA showed biofilm formation only in four (3.47%) strains. Scanning electron micrographs showe...

Identification and Detection of Biofilm Producing Staphylococcus Aureus and Its Antibiogram Activities

2021

Objectives: The main aim of this work is to determine the antibiogram profile of biofilm-producing Staphylococcus aureus from various clinical specimens of the patients. Methods: Various bacterial cultures of non-repeated clinical specimens from a total of 3388 patients were determined using standard microbiological and biochemical methods. Results: Out of 3388 only 604 (17.02%) displayed growth positive. A total of 65 (51.58%) S. aureus isolates were recovered, 25 (38.46%) were identified as methicillin-resistant S. aureus (MRSA) by Cefoxitin (30 μg) disk diffusion technique, of which majority were from pus/wound swab 22 (37.29%). The antibiogram of the isolates was analyzed by Kirby-Bauer disk diffusion technique analyzing Linezolid to be the most effective drug with susceptibility of 100% to both MRSA and methicillin-sensitive S. aureus, followed by vancomycin, tigecycline, and tetracycline. In vitro biofilm production by tissue culture plate (TCP) and Congo red agar method detec...

Evaluation of Biofilm Formation in Staphylococcus aureus Clinical Isolates

medicallaboratory journal, 2019

Background and Objectives: Staphylococcus aureus is a common cause of nosocomial infections. The ability of S. aureus to form biofilm and acquire antimicrobial resistance has made this organism a major health problem. In this study, we investigate the biofilm-forming ability of S. aureus isolates from clinical samples. Methods: Sixty S. aureus isolates from clinical specimens were collected from the 5th Azar Hospital of Gorgan (Iran) in 2018. The isolates were identified using conventional methods including Gram staining and biochemical tests (catalase and coagulase). Biofilm formation by S. aureus isolates was evaluated using a microplate-based method. Results: Of 60 S. aureus isolates, 47 (78.3%) strains were identified as biofilmforming and 13 (21.7%) strains were non-biofilm-forming. Conclusion: The high prevalence of biofilm-producing S. aureus isolates in the 5 th Azar hospital of Gorgan could pose a major health challenge with serious consequences for hospitalized patients. Therefore, it is crucial to disinfect and sterilize hospital surfaces and equipment effectively to minimize the risk of contamination and spread of bacteria in the hospital settings.

Antibiotic susceptibility pattern of biofilm producing Staphylococci isolated from different clinical samples

Background: Biofilm mediated infection by Staphylococci have a significant negative impact on patient health and necessitate reliable method for detecting biofilm producers. The ability of isolates to produce biofilm make them resistant to host immune response as well as available antibiotics. This study aims to detect biofilm producing ability among clinical staphylococci by phenotypic methods and presence of icaAD genes as well as their antibiotic profile. Methods: A total of 4063 different clinical specimen received in the tertiary care hospital of Nepal were examined and Staphylococci were identified following standard microbiological procedure. The antibiotic resistivity pattern was detected by Kirby Bauer disc diffusion method whereas biofilm formation was detected by three phenotypic methods viz. congo red agar (CRA), tube method (TM) and tissue culture plate (TCP) method. Furthermore, icaAD genes were detected by PCR method. Results: A total of 161 Staphylococci were isolate...

Biofilm Producing Clinical \u3ci\u3eStaphylococcus aureus\u3c/i\u3e Isoates Augmented Prevalence of Antibiotic Resistant Cases In Tertiary Care Hospitals of Nepal

2018

Staphylococcus aureus, a notorious human pathogen, is a major cause of the community as well as healthcare associated infections. It can cause a diversity of recalcitrant infections mainly due to the acquisition of resistance to multiple drugs, its diverse range of virulence factors, and the ability to produce biofilm in indwelling medical devices. Such biofilm associated chronic infections often lead to increase in morbidity and mortality posing a high socio-economic burden, especially in developing countries. Since biofilm formation and antibiotic resistance function dependent on each other, detection of biofilm expression in clinical isolates would be advantageous in treatment decision. In this premise, we attempt to investigate the biofilm formation and its association with antibiotic resistance in clinical isolates from the patients visiting tertiary health care hospitals in Nepal. Bacterial cells isolated from clinical samples identified as S. aureus were examined for in-vitro...

Biofilm Producing Clinical Staphylococcus aureus Isolates Augmented Prevalence of Antibiotic Resistant Cases in Tertiary Care Hospitals of Nepal

Frontiers in Microbiology

Staphylococcus aureus, a notorious human pathogen, is a major cause of the community as well as healthcare associated infections. It can cause a diversity of recalcitrant infections mainly due to the acquisition of resistance to multiple drugs, its diverse range of virulence factors, and the ability to produce biofilm in indwelling medical devices. Such biofilm associated chronic infections often lead to increase in morbidity and mortality posing a high socioeconomic burden, especially in developing countries. Since biofilm formation and antibiotic resistance function dependent on each other, detection of biofilm expression in clinical isolates would be advantageous in treatment decision. In this premise, we attempt to investigate the biofilm formation and its association with antibiotic resistance in clinical isolates from the patients visiting tertiary health care hospitals in Nepal. Bacterial cells isolated from clinical samples identified as S. aureus were examined for in-vitro biofilm production using both phenotypic and genotypic assays. The S. aureus isolates were also examined for susceptibility patterns of clinically relevant antibiotics as well as inducible clindamycin resistance using standard microbiological techniques and D-test, respectively. Among 161 S. aureus isolates, 131 (81.4%) were methicillin resistant S. aureus (MRSA) and 30 (18.6%) were methicillin sensitive S. aureus (MSSA) strains. Although a majority of MRSA strains (69.6%) showed inducible clindamycin resistance, almost all isolates (97% and 94%) were sensitive toward chloramphenicol and tetracycline, respectively. Detection of in vitro production of biofilm revealed the association of biofilm with methicillin as well as inducible clindamycin resistance among the clinical S. aureus isolates.

Evaluation of Biofilm Formation by Staphylococcus aureus recovered from Clinical Samples of patients attending a Tertiary-care Hospital in North-eastern Nigeria

Archives of Clinical Microbiology, 2020

Staphylococcus aureus is a classical pathogen that is implicated in a wide range of diseases. It is a resident flora of the human skin and can easily contaminate open wounds and gain access into circulation and inflict damage to the host. This study is designed to identify Staphylococcus aureus from various clinical samples and determine the isolates’ ability to form biofilm. Eighty-six (86) clinical samples were collected aseptically from patients attending University of Maiduguri Teaching hospital. The samples were processed using standard microbiological methods for the identification of S. aureus. Samples were cultured on 5% blood agar and presumptive S. aureus isolates were further confirmed by biochemical identification at the Microbiology Laboratory of University of Maiduguri, Nigeria. Biofilm formation was analysed using three detection methods which comprise of Congo red agar (CRA) method, Tube method (TM) and Microscopy method (MM). Out of the eighty-six (86) samples proce...